Bosch 520-PN-N User Manual

520 PN
INDOOR MODEL
Flow Modulated with Standing pilot
Suitable for heating potable water only - Not approved for space heating purposes
(Intended for variable flow applications with steady cold water inlet temperatures)
520-PN-N
520-PN-L
6 720 644 947 (2011/05) US
Warning: If the information in this manual is not
followed exactly, a fire or explosion may result
causing property damage, personal injury or death.
Do not store or use gasoline or other flammable
vapor and liquids in the vicinity of this or any other
appliance.
Improper installation, adjustment, alteration,
service or maintenance can cause injury or
property damage. Refer to this manual. For
assistance or additional information consult a
qualified installer, service agency or the gas
supplier.
In the Commonwealth of Massachusetts this
product must be installed by a licensed plumber or
gas fitter.
Upon completion of the installation, these
instructions should be handed to the user of the
appliance for future reference.
What to do if you smell gas
• Close gas valve. Open windows.
• Do not try to light any appliance
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire
department.
• Installation and service must be performed by a
qualified installer, service agency or the gas supplier.

Bosch 520-PN-N Specifications

General

Brand	Bosch
Model	520-PN-N
Category	Water Heater
Language	English

Summary

Safety Warnings and Hazards

Danger: Burn Hazard from Hot Water

Details the risk of severe burns or death from water temperatures over 125°F.

Appliance Details and Specifications

Gas and Water Connections

Details gas connection requirements, inlet pressures, and water connection specifications.

Unpacking and General Safety Rules

Instructions for unpacking the heater and general rules for safe operation.

Installation and Gas Type Verification

Guidelines for verifying gas type, ensuring safe installation, and checking for proper clearances.

Dimensions and Installation Clearances

Installation Instructions Introduction

Heater Placement and Clearances

Guidelines for selecting a proper location and maintaining required clearances around the heater.

Heater Mounting Procedures

Combustion Air Requirements

Venting Requirements

Horizontal and Vertical Venting

Explains permitted and prohibited venting configurations for horizontal and vertical installations.

Masonry Chimney Venting

Guidelines for using masonry chimneys with the water heater, including liner requirements.

Gas Piping and Connections

Gas Line Sizing

Provides guidance on sizing gas supply piping based on BTU demand and local codes.

Measuring Gas Pressure

Water Connections and PRV Installation

Details water connection requirements and the mandatory installation of a pressure relief valve (PRV).

Operation Instructions

Safety Before Operation and Gas Leak Procedures

Critical safety information and actions to take if a gas smell is detected.

Recirculation Application

Guidance on a recirculation application using the water heater with an external minitank.

Lighting and Shutting Off Appliance

Pilot Lighting Procedures

Detailed steps for lighting the pilot burner using the piezo igniter.

Appliance Shutdown Procedure

Instructions on how to safely turn off the water heater.

Setting Water Temperature and Draining

Adjusting Water Temperature

How to adjust the water temperature using the control knob and slide.

Draining the Water Heater

Procedure for draining the water heater to prevent freeze damage.

Maintenance Intervals and Water Valve Service

Inspecting Inlet Water Filter

Procedure for inspecting and cleaning the water inlet filter screen.

Lubricating the Water Valve

Detailed instructions for lubricating and servicing the water valve assembly.

Component Maintenance and Descaling

Main Burner Maintenance

Inspection and cleaning of the main burner assembly for optimal performance.

Heat Exchanger and Vent Cleaning

Cleaning the vent assembly and heat exchanger fins for soot and debris.

Mineral Scale Build-up and Descaling

Procedures for descaling the heat exchanger to prevent mineral build-up.

Troubleshooting Guide

Pilot Light Issues

Troubleshooting steps for when the pilot light does not light or extinguishes after ignition.

Pilot Outage During Hot Water Use

Diagnosing why the pilot light may go out during or after hot water usage.

Burner Ignition and Temperature Fluctuations

Steps for issues with burners not lighting and fluctuating hot water temperatures.

Addressing Overly Hot Water

Solutions for when the water temperature is excessively hot.

Water Temperature and Pressure Issues

Troubleshooting for insufficient hot water, burners igniting unexpectedly, low pressure, and noise.

Burner Operation and Flame Quality

Diagnosing issues with burners not operating cleanly or producing yellow flames.

Protecting the Environment

Recycling and Water Saving

Guidelines for responsible disposal of components and conserving water resources.

Interior Components Overview

Detailed Components Diagram

Parts List

Lifetime Limited Warranty

Warranty Coverage and Exclusions

Outlines what the warranty covers, parts not included, and potential exclusions.

Warranty Conditions

Specifies the conditions under which the limited warranty becomes void.

Notes